Question

A baseball is thrown up in the air from a height of 3 feet with an initial velocity of 23 feet per second. When does the baseball hit the ground

Answer 1

You need a formula from your basic physics class:\[s(t)=\frac{at^2}{2}+v_0t+s_0\]In the case of a projectile motion problem like this one, a = g = -32 ft/sec^2. Just substitute that, and the information from the problem v0=23 ft/sec and s0=3, then solve for s(t)=0.